Dateline SAN FRANCISCO, Ca., 24 March 2026— A hearing was held on a motion for a preliminary injunction in the case of Anthropic PBC v. U.S. Department of War et al. in Courtroom 12 on the 19th floor of the Phillip Burton Federal Building, the Hon. Judge Rita F. Lin presiding. About 35 spectators in the gallery (journalists and other members of the public, including the present writer) looked on as Michael Mongan of WilmerHale (lead counsel for the plaintiff) and Deputy Assistant Attorney General Eric Hamilton (lead counsel for the defendant) argued before the judge. (The defendant also had another lawyer at their counsel table on the left, and the plaintiff had six more at theirs on the right, but none of those people said anything.)

For some dumb reason, recording court proceedings is banned and the official transcript won't be available online for three months, so I'm relying on my handwritten live notes to tell you what happened. I'd say that any errors are my responsibility, but actually, it's kind of the government's fault for not letting me just take a recording.

The case concerns the fallout of a contract dispute between Anthropic (makers of the famous Claude language model assistant) and the U.S. Department of War. The Department wanted to renegotiate its contract with Anthropic to approve all lawful uses of Claude. Anthropic insisted on keeping terms of use prohibiting autonomous weapons and mass surveillance of Americans, and would not compromise on those two "red lines".

Judge Lin began by describing her understanding of the case. Everyone agrees that the Department of War is free to just stop using Claude, the judge said. What was at issue was three additional actions taken by the government: banning other federal agencies from using Claude (as announced by President Donald Trump), announcing a secondary boycott forbidding federal contractors from doing their own business with Anthropic, and formally designating Anthropic as a supply chain risk. The present hearing was to help the Court decide whether to grant Anthropic's request for an injunction, a court order to stop the government's actions against Anthropic for now until a longer legal process had time to play out. Judge Lin said that she found it troubling that it looks like the Department of War is trying to punish Anthropic for trying to bring public scrutiny to a contract dispute.

The previous day, Judge Lin had assigned homework questions for the lawyers to answer during the hearing, which she proceeded to read.

The first question concerned Secretary Hegseth's 27 February Tweet declaring that "Effective immediately, no contractor, supplier, or partner that does business with the United States military may conduct any commercial activity with Anthropic", and that "This decision is final." Judge Lin asked the defendant's counsel if they agreed that Secretary Hegseth lacked the authority to issue such a broad directive.

Hamilton replied that the language needed to be read in the context of the previous sentence, that the Secretary was "directing the Department of War to designate Anthropic a Supply-Chain Risk". A social media post announcing the process of making the supply chain risk designation was not itself legally binding, and that's how the post was understood by the Department.

Judge Lin expressed skepticism: "You're standing here saying, we said it, but we didn't really mean it." How could Anthropic know? Did the Department of War do anything to take back the Secretary's false statement? Hamilton said that the Department had clarified its position in a letter to Anthropic, and in their filings for the present case.

Judge Lin asked about the scope of the directive: if a contractor that sold toilet paper to the military also used Claude Code in their business, would that be acceptable? Hamilton said that it would: "For non-DoW work, that is not the Department's concern." Judge Lin asked why Secretary Hegseth would say what he did if it had no legal effect. Hamilton said he wasn't sure, but that the administration was committed to transparency.

Judge Lin asked the plaintiff's counsel if there was still irreparable harm to Anthropic given that the Secretary's secondary boycott announcement had no legal effect. Mongan said that while he appreciated the concession by his "colleague" (Hamilton), it was a problem that this matter was only being clarified now, on 24 March: Secretary Hegseth's 27 February Twitter directive had been read by millions who would read it to say exactly what it said. The letter served to Anthropic on 4 March had not provided clarity, either. The government's lawyers backing away from the original directive wasn't sufficient; "authoritative clarity" was needed to inform people who have Twitter accounts ("X accounts", Mongan said) but not PACER accounts (PACER being the electronic court records system), who weren't following the present proceedings. Hamilton replied that nothing needed to be clarified; he had already explained how the Department of War understood Hegseth's post and disabused the plaintiff of their interpretation.

The next question concerned Secretary Hegseth's failure to include a statutorily required discussion of "less intrusive measures" that were considered before pursuing the supply chain risk designation in his notice to Congress. Hamilton agreed that the notification to Congress hadn't included that needed detail, but that this had no bearing on whether an injunction should be granted. Anthropic had no right to enforce that requirement as a third party; the matter was between the Department of War and Congress. The Department should be given three days to amend their notification to Congress, Hamilton argued, and it might end up being classified. Mongan replied that the Administrative Procedures Act was clear that the notification was intended for Congress to review the designation; it wasn't supposed to just be an FYI.

The next question was about the "less intrusive measures". The defendant had argued that the Department simply transitioning away from directly using Claude themselves was insufficient to mitigate supply chain risks, because the Department also needed to avoid Claude becoming entwined with the Department's systems through contractors. (For example, Palantir's Maven targeting system had been widely reported to use Claude, but the Department's contract for Maven was with Palantir, not Anthropic.) Judge Lin asked, how broadly did that sweep? If a contractor used Claude Code to write software for the Department, would that be permitted? Hamilton said that that particular fact pattern wouldn't run afoul of the supply chain risk designation. He insisted, however, that the Department shouldn't have to go contract by contract to make sure Claude wouldn't infect DoW systems; Congress had authorized the supply chain risk designation as a tool for this kind of situation.

In reply, Mongan said that the defendant's argument was attempting to normalize the invocation of the supply chain risk designation, which was a narrow authority and not the normal way to respond to contract disputes under existing procurement law. It appeared that Secretary Hegseth had made the decision on 27 February, and people in the Department were scrambling to fulfill the procedural requirements after the fact, and not even successfully.

Judge Lin asked the plaintiff's counsel what evidence showed that Anthropic had the access to Claude after delivering it to the Department such that Anthropic could engage in sabotage if they wanted to. Hamilton said that the Department would require updates to the software; sabotage could occur then. Judge Lin asked if that the Department would have to accept any updates (as contrasted to Anthropic being able to update the software unilaterally). Hamilton said he wasn't sure whether the Department had taken a position on that; an audit was underway.

Judge Lin commented that most IT vendors presumably had the capability to sabotage their product if they wanted to. "With every software vendor, it is a trust relation on some level," she said. Was it the Department's view that stubbornness in insisting on contracting terms made a vendor a supply chain risk?

No, said Hamilton, it was about raising concerns to the Department about lawful uses of the software. The Department had not been working with Anthropic for long. Anthropic's resistance to approving all lawful uses, combined with their behavior in discussions, had destroyed trust. Judge Lin said that what she was hearing was that Anthropic's offense in the Department's eyes consisted of asking annoying questions. Hamilton said he didn't think that was the best interpretation of the record. The possibility of Anthropic installing a kill switch in the future was an unacceptable risk to the Department. Judge Lin asked why questioning usage terms would lead to installing a kill switch: "I'm not seeing the connection here," she said.

Judge Lin gave the plaintiff the opportunity to respond. "Where to start, your honor," said Mongan. He said that the defendant's rationale seemed to shift. It was hard for him to square the supply chain risk designation with the claim that the problem was Anthropic's resistance to approving "all lawful use". Everything Anthropic had been accused of was above board. Arguing for usage restrictions up front doesn't make one an adversary. A saboteur wouldn't start a public spat. Moreover, Anthropic couldn't alter Claude after it had already been deployed to the government's cloud.

The next homework question (concerning the date of a memo signed by Undersecretary of War Emil Michael) was skipped because it had already been answered in a new declaration by Undersecretary Michael that very day.

The final question was for the plaintiff's counsel: what evidence in the record established that the other federal agencies listed in the complaint besides the Department of War were using Claude? Mongan said that they hadn't introduced such evidence yet, but could add a declaration quickly. Judge Lin asked if the plaintiff could do so by 6 p.m. that day, to which Mongan agreed.

Hamilton objected that the court should not accept late evidence; the plaintiff had chosen to file this suit. Judge Lin said she had been trying to let everyone submit evidence; the government had submitted evidence (Undersecretary Michael's second declaration) that morning. Hamilton asked for at least 24 hours for a potential response, which Judge Lin granted, saying that 6 p.m. the next day was fine.

Then Judge Lin gave both parties a chance to present any additional arguments to the Court, starting with the defendant. Hamilton argued that Anthropic's case failed for at least three reasons: refusing to deal with the government wasn't an expressive act (contrary to the complaint's claims that the government was violating Anthropic's First Amendment rights by retaliating against Anthropic for its expression of safety red lines), the President and War Secretary are entitled to substantial deference in how they run the government, and that the Department would have acted the same way regardless.

In reply, Mongan said that the Court had heard most of the plaintiff's arguments and that they were likely to succeed on the merits should the case continue. He asked if the Court had any questions. There was a back-and-forth between Judge Lin and Mongan about the Pickering factors that I didn't quite follow.

Judge Lin asked whether the plaintiff agreed that the Department of War could stop the use of Claude by contractors. Mongan said he wanted to be cautious about making concessions about hypotheticals. All Anthropic was seeking in an injunction was the status quo of 27 February (before Hegseth's social media post). Nothing would prevent the Department from doing things it could have done on 27 February through ordinary procurement processes. The plaintiff understood the need for deference to national security concerns, but sought to prevent the irresponsible and continuing harm of the Department's actions, harm that didn't just stop at Anthropic, as had argued by the various amicus curiæ.

Judge Lin said she anticipated issuing an order within the next few days, and court was adjourned.